#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <signal.h>
#include <unistd.h>
#include <stdlib.h>
#include <assert.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
/*
ssize_t recv(int sockfd,void *buf,size_t len,int flags);
recv读取sockfd上的数据，buf和len参数分别指定读取缓冲区的位置和大小。
*/
#define BUF_SIZE 1024
int main(int argc,char*argv[])
{
    if(argc <=2)
    {
        printf("usage: %s ip_address port_number \n",
        basename(argv[0]));
        return 1;
    }

    const char* ip = argv[1];
    int port = atoi(argv[2]);

   

    /*创建一个IPv4 socket地址*/
    struct sockaddr_in address;
    bzero(&address,sizeof(address));
    address.sin_family = AF_INET;
    inet_pton(AF_INET,ip,&address.sin_addr);
    address.sin_port= htons(port);

    int sock = socket(PF_INET,SOCK_STREAM,0);
    assert(sock>=0);

    int ret = bind(sock,(struct sockaddr*)&address,sizeof(address));
    assert(ret != -1);
    ret = listen(sock,5);
    assert(ret !=-1);

    struct sockaddr_in client;
    socklen_t client_addrlength = sizeof(client);
    int connfd = accept(sock,(struct sockaddr*)&client,&client_addrlength);
    if(connfd <0)
    {
        printf("errno is: %d\n",errno);
    }
    else{
        char buffer[BUF_SIZE];
        memset(buffer,'\0',BUF_SIZE);
        ret = recv(connfd,buffer,BUF_SIZE-1,0);
        printf("got %d bytes of normal data '%s'\n",ret,buffer);

        memset(buffer,'\0',BUF_SIZE);
        ret = recv(connfd,buffer,BUF_SIZE-1,MSG_OOB);
        printf("got %d bytes of oob data '%s'\n",ret,buffer);

        memset(buffer,'\0',BUF_SIZE);
        ret = recv(connfd,buffer,BUF_SIZE-1,0);
        printf("got %d bytes of normal data '%s'\n",ret,buffer);

        close(connfd);
    }
    close(sock);
    return 0;
}

